/Engine/Source/Editor/MaterialEditor/Public/MaterialEditorUtilities.h
Get a preview material render proxy for an expression
FMaterialRenderProxy* Preview for this expression or NULL
static [FMaterialRenderProxy](API\Runtime\Engine\Materials\FMaterialRenderProxy) * GetExpressionPreview ( const class [UEdGraph](API\Runtime\Engine\EdGraph\UEdGraph) * Graph, [UMaterialExpression](API\Runtime\Engine\Materials\UMaterialExpression) * InExpression )